1. Field of the Invention
The present invention generally relates to a driving circuit, and more particularly to a backlight driving circuit and a liquid crystal display device having the backlight driving circuit.
2. Description of Prior Art
A liquid crystal display device mainly comprises a liquid crystal panel and a backlight module. The backlight module is utilized for providing light when the liquid crystal panel displays an image. Light emitting diodes (LEDs) are utilized as a light source in the conventional backlight module. A backlight driving circuit provides a required driving current for driving the light source.
The light source comprises a plurality of light emitting diodes. Since a thickness of the liquid crystal panel is required to be narrower, the light emitting diodes are divided into a plurality of light emitting diode bars in parallel. Each of the light emitting diode bars is electrically coupled to the backlight driving circuit via a connector. More particularly, a positive polarity end of each of the light emitting diode bars is electrically coupled to a positive polarity end of an output voltage of the backlight driving circuit via the connector, and a negative polarity end of each of the light emitting diode bars is electrically coupled to a negative polarity end of the output voltage of the backlight driving circuit.
When the positive polarity end of each of the light emitting diode bars is electrically coupled to the negative polarity end of the output voltage of the backlight driving circuit via the connector and the negative polarity end of each of the light emitting diode bars is electrically coupled to the positive polarity end of the output voltage of the backlight driving circuit, that is, the two ends of each of the light emitting diode bars are electrically to a reverse output voltage, the light emitting diodes of each of the light emitting diode bars are broken down and destroyed.
Consequently, there is a need to solve the problem that the light emitting diodes of each of the light emitting diode bars are destroyed when the positive polarity end and the negative polarity end of each of the light emitting diode bars are electrically coupled to the reverse output voltage in the prior arts.